深层低渗凝析气藏反凝析特征研究

深层低渗凝析气藏数量越来越多，了解其反凝析特征是气藏开发正确决策的重要基础。以中原油田的深层低渗凝析气藏为主要研究对象，通过CVD测试及真实岩心衰竭实验测试，研究了深层低渗凝析气藏的反凝析特征。研究结果表明：PVT筒的定容衰竭与多孔介质中的衰竭特征有较大的差异，因此应尽可能采用岩心衰竭实验研究深层低渗凝析气藏的真实反凝析相态特征；中原油田深层低渗凝析气藏衰竭开发过程中反凝析呈中等偏低水平。近井地层的反凝析液堆积速度较慢，最大反凝析液饱和度值对应的地层压力与气藏标定的废弃压力接近。这表明中原油田深层低渗凝析气藏比较适合于采用衰竭方式开发；中原油田深层低渗凝析气藏衰竭开发过程中产生的凝析油饱和度小于临界流动饱和度，析出的凝析油不会产生反蒸发，因此在气藏开发过程中防止反凝析污婆就显得非常重要．

Study on Retrograde Condensate Characteristics of Deep Condensate Gas Reservoirs with Low Permeability

With more condensate gas reservoirs being found,it is the important foundation of developing the gas reservoirs accurately to comprehend the condensate characteristics.Based on deep condensate gas reservoirs with low permeability in Zhongyuan oilfield,the condensate characteristics are studied by CVD test and actual core depletion experiments.The results show that there exists great difference on the depletion features between the PVT cells and porous media.So it needs use actual core depletion to study the real condensate phase behavior in deep condensate gas reservoirs with low permeability.The condensation of deep condensate gas reservoirs is below the moderate level during the process of the depletion experiment in Zhongyuan oilfield.The accumulating rate of condensate liquid near the well bore is slow.The reservoir pressure corresponding to maximum condensate saturation is close to the abandonment pressure that is calibrated.That indicates that deep condensate gas reservoirs with low permeability in Zhongyuan oilfield are suitable to develop by the depletion way.The condensate saturation caused by the development of deep gas reservoirs with low permeability in Zhongyuan oilfield is below the critical mobile saturation.The condensate liquid cannot be vaporized.So it is very important to prevent the condensate liquid from pollution in developing the deep condensate gas reservoirs.